Certain materials require specialized packaging for storage and dispensing of the material. For example, with respect to fluid or fluid-like (that is, having an ability to flow either due to gravity or to an applied force) dental materials, the materials may be light sensitive or the like, requiring packaging the prevents premature exposure of the material to light. Further, dental materials such as adhesives, often contain multiple components that need to be separated during storage but that must be mixed immediately prior to use. Further still, it is often necessary to use only a small amount of a material for a given dental procedure. Hence, it is desirable to store and dispense such materials in single use or “unit dose” sizes.
Heretofore, storage and packaging of dental materials was often accomplished with small opaque bottles. While such bottles often provided for ease of storage, they do not lend themselves well to efficient dispensing operations. Further, when two or more components are to be mixed, the materials have to first be accurately measured.
Historically, paste/paste products have been packaged in double-barrel syringes with motionless mixing tips. MixPac, TAH industries and Plas-Pak are several companies that manufacture and market double-barrel syringes and mixtips. Double barrel syringes are available in standard 2.5 and 5 mL formats. These syringes are suitable for unit-dose applications where the unit of use is approximately 2.5 and 5 mL, but when the unit of use is less than 2.5 mL they are only suitable for multi-use applications. Therefore, there is a need for a unit-dose, auto-mixing system for paste/paste products where the unit of use is equal to or less than 2.5 mL.
For example, when cementing a crown onto a tooth, approximately 0.3 mL of cement is needed. It would be wasteful to package a unit-dose amount in a double barrel syringe that was designed for 2.5 mL. As a result, the only viable auto-mix packaging solution for paste/paste cements is a multi-use double barrel syringe.
The present invention seeks to create a true unit-dose packaging and delivery system for the range of paste/paste products that are used in volumes of 2.5 mL or less. In order to achieve the small volumes needed for some dental products a small cartridge was conceived (sometimes referred to as the base unit cartridge, see also FIG. 15). A cartridge that delivers a net 0.3 mL is practical with regards to this design. Adding incremental extensions onto the length of the base cartridge can make cartridges of larger net volumes.
Another example is when a dental practitioner takes an impression by the dual-phase technique. Users commonly back-fill an intra-oral syringe with low viscosity mixed impression material using a standard 50 mL cartridge and mixtip. GC America manufactures an intermediate intra-oral syringe for the dual-phase technique. The intra-oral syringe improves the technique of applying low viscosity impression material to the prepared tooth. Once the mixed product is in the syringe, it must be used immediately or else it would set up due to the reaction of mixing the two components. The syringe is usually loaded with more than enough material to perform the procedure and must be cleaned and sterilized after use. This procedure provides good clinical technique, but it is cumbersome and wastes a lot of product.
The present unit-dose cartridge delivery system offers the practitioner the same syringe technique while improving ease of use. The system can be assembled and staged prior to use thereby reducing the complexity of the technique and eliminating the critical timing needed to use a back-filled syringe. The technique of using a back-filled syringe wastes about 3 mL of product in order to deliver the 1 mL needed for the procedure (approximately 2 mL in the mixtip and 1 mL in the intra-oral syringe). The system wastes only about 0.3 mL of product because the mixtip is much smaller than that of the standard 50 mL cartridge system and an intermediate delivery syringe is not needed.
It should therefore be understood that the present cartridge delivery system reduces wasted product and packaging, improves ease of use and provides true unit-dose, auto-mixing packaging options for products that are used in amounts of 2.5 mL and less.
A need exists therefore, for a package for storing a material and for dispensing the material, especially a dental material such as a multi-component adhesive. The package should protect the material to premature exposure to the environment; it should keep multiple components separate during storage; it should facilitate the dispensing and mixing of premeasured quantities of the material; and, it should be useful for unit dose quantities of the material to be packaged. A need also exists for an improved delivery and dispensing system for use with such a package.